In a so-called traction-type elevator system having a sheave driven by a motor to drive ropes wound on the sheave, encoders for detecting the velocity of the elevator car are installed at the output axis of the motor through a timing belt or the like, whereby the velocity of the elevator car is detected based upon the revolutions per minute of the motor output axis.
However, in the elevator system using a linear motor which has been developed as the driving mechanism, a counterweight or the elevator car itself is directly and linearly driven by the linear motor, and the sheave onto which the ropes are guided acts as an idler rotatably driven by the rope. Thus there is no motor corresponding to that of the traction-type elevator.